Improved spring-tension regulator



PATENTED MAR. 8, 1864.

T. SILVER. SPRING TENSION REGULATOR.

. l/IW/ I I WLTIMSSM." 7f

"MM Ohm- UNITED STATES THOMAS. slnvnn or NEW YORK, n. v.

, lMPROVED 'SPRING-T PATENT OFFICE.

ENSION neon LATOR.

Specification forming part ofrLettcis Patent No. 11,868. datcdh'larchfi,1864.

To all whom it maycon'cern:

L Be it known that I, THOMAS SiLvnR, of the city of- Nc'w York, in thecounty and State of New Yorlghaveinvented a certain new and usefulSpring-Tension Regulator; and I do hereby declare that the following isa full, clear, and exact description lit. the same,-reference being hadto the accompanying drawings, making a part of this'speeilication, andto the letters of reference marked thereon.

When it is desirable to compress or extend a spring, the intensity ofthe forcef zpeplied must be constantly increased in proportion tov theincreased resistance of the spring, as the degree of force which willextend or compress. it one inch from its normal position must be greatlyincreased to move it an atd'Ltional inch. In the case, for example,'0fthe ordinary application of a spring safety-valve to a boiler, the valvemay begin to open by the pressure of steam at. the point desired; but itwill require aconsrderable additional pressure to open the valve stillfarther to permit the escape of an amount of steamsutfieient to relievethe boiler. It is this constant increase of tension in a spring that hasrendered the application of a weighted lever preferable in many cases,as, for instance, on a sea-going steamer where the motion of the vesselconflicts with the inertia of the weight and ma terially al'l'ecls itsutility. \\"hen a vessel has a stormy voyage, the relief of the load onthe safety-valve, owing to the'pitching and rolling of the vesselaffecting the stability of the weight, may occasion the-losscf a largepercentage of steam, and it will be understood that this isihe morelikely to occur because the effect of the weight on the valve is broughtinto a condition approximzu ingan eipiilihrium by the slight differencebetween. the working- .pressure and the blowing-oft point.

The object or my invention is to equalize or to vary in effecttheincreasing tension 0t any known form or variety of spring, whether in astate of extension or contraction, as may he required for the diiferentmodifications ol' r e-- sistance and power involvedin mechanical pa 1'-poscs. Xihen it is desired, for example, to

use a spring as asnbstitutc for a-weight in the noading, of asafety-valvelever of a steam- )oiler under circumstances of locomotionwhich miglitislisturb thc action of the forcddit is torbr m a means ofadjusting a spring to such an equilibrium of force that it shall resistpermanently a determined pressure upon the valve; but when the saidpressure may be exceeded the valve-lever maybe allowed to rise toopenthevalve in the same manner as if it had been confined by a weight,and thewhole throw or motionof thelever will be madewithout the increase ofresistance that would be the case with aspring applied-in the ordinarymanner. To attain this-=ob iect my invention consists in combining, the:spring transmitted in such a manner that it is first applied to the longradius, and continued by the turning. of the eccentric, so that theleverage of the eccentric'is diminished asthe'int-ensity of the springis increased, the greater force of the spring having ashortcrqlever tooperate upon; and in a simi' ar manner by passing the chef n or othcrfletible connection of the spring and valve (or other machinery to whichthe tercnce of the eccentric, the power of the spring is transmittedfrom the eccentriUW'ith a constant increase of leverage in proportion totheincrcasein tension of the spring,so that the increased force of thespring operating upon its shorter lever has also its resistance tionforthe variations of the force of the spring by the leverages through whichit is app] ied is, that when th degree of eccentricity is properlyproportioned the entire range of the expansion or cont raction of aspring willbe rendiered uni form and liilllill,tllltl by changing theiarh'ount ot' eccentricity the equilibrium will be destroyed, on the oneha'nd,by shiftingthe axisnl' tilt-eccentric so that it becomes merely apl iiley the action of the spring is unchanged,- and on the other byshifting the axis beyond 1 in. pointol'equilibrium the action ofthespring will be diminished in intensity instead of ta.

creased. I

To enable others skilled in the art to which it app gptnins to make anduse my invention, 1.

""wil'l' proceed to describe its construction and I operation withreference to the drawings. 1 l igurcl is a front view of my saidinvent-i n I ,g'raviflyoff'a iveig-lihthe object of nfiyinvent i on with'a'portiou of the l'ranieunnovcd, so as to with an eccentriqthroughwhich its power is spring is applied) around one-half the cireumplacedupon a. longer lever, occasioningacon-- version of the increased forceand lessened.- range of the spring to a diminished force and extendedrange. T he result of this compensa exhibit the spring which is in itsuormal'posi tion and Fig. 2is a sideview of the same.

Fig. 3% a front view with the spring extended and aportion of the framealso removed. Theeecentricc is made with a slot,through which passes theaxis 6,. which is maintained in -any required position of eccentricityby means 'of the screw 0. The chain (1 passes over the ethentrie andisatiaehed to it at the screw 0 or elsewhere, so that it moves with thecocentric, and itis connected atone side to the spring 6, anglat' theother to a rod, f, by the loop, in the end of whiehlt may be connectedregulated as may be required. The axis b is siipported by the vibratingframe w,on which it rolls,instead of beingeonfined in journals in theframes, bywhich means the friction is greatly diminished.

\l'hen it is d sirable to have 1.1 increased leverage motion withoutenlarging the ec same purpose, or eccentrics of different sizes may beused, so that an elliptic or indie-nubher or other spring of smallmovement may afford a large, range of application. \Vith a ehronometer0r true spiral spring one end of the spring should be attached to theshaft,and the opposite end to a ratehet-wheel which can be turned andsecured in adjusting the tension of the spring.

Having thus described the manner in which I prefer tomake and apply mysaid invention, I wish it tobe understood that I do not confineinyselt'to that precise manner of construe tion orapplieationoi't-heprinciple of varying the leverages to said differentdegrees of tension; hut

\Vlrat Ido claim as my invention is' The combination of a'spring with ancecentrie, substantially as described for the pm pose specified.

rn'mL-ts sinvna.

